An individual who works in a hazardous environment, in which the surrounding air is contaminated or otherwise harmful, may wear respiratory protection equipment that delivers breathing air to the individual. The respiratory protection equipment may include a facemask that covers at least a portion of the face of the wearer. Optionally, the respiratory protection equipment includes a supply of breathing air that delivers fresh breathing air to the facemask. Facemasks include half masks, which may only cover the nose and mouth of the wearer, and full facemasks, which may not only cover the nose and mouth but also the remainder of the face of the wearer. Full facemasks may be worn in environments where exposure to the surrounding air may harm the eyes or skin of the wearer.
Full facemasks typically include a lens (or visor or face shield) and at least one functional component that is located below the lens piece proximate to the mouth of the wearer. The functional components may include at least one of an air regulator, voice emitter, filter, exhalation port, or hydration port. Often, facemasks include more than one functional component. For instance, the facemasks may include two filters located on opposite sides of the facemask and an exhalation port positioned between the two filters. Although full facemasks may have similar fundamental elements (e.g., lens piece and one or more functional components), these fundamental elements may vary greatly based on the intended application of the facemask. For example, firefighters may wear different types of facemasks than the types of facemasks worn by law enforcement during riot control. Each different type of facemask, however, may have a different design.
With respiratory protection equipment, it is often necessary and expensive to undergo fit testing for each facemask variant donned by an individual. During fit testing, the facemask is worn by the individual while certain testing procedures are performed. For example, the fit test may determine whether the facemask is suitably comfortable for certain exercises and whether the facemask has any leaks with respect to the surrounding environment. As noted above, however, facemasks that are used in different applications have different designs. It may be desirable to have a facemask that can be reconfigured without having to re-perform a fit test with the re-configured facemask. In addition to the above, manufacturers often desire simpler and less expensive methods of manufacturing items, including full facemasks.